It is not safe to close an event channel from the QEMU main thread when that channel's poller is running in IOThread context. This patch adds a new xen_device_set_event_channel_context() function to explicitly assign the channel AioContext, and modifies xen_device_bind_event_channel() to initially assign the channel's poller to the QEMU main thread context. The code in xen-block's dataplane is then modified to assign the channel to IOThread context during xen_block_dataplane_start() and de-assign it during in xen_block_dataplane_stop(), such that the channel is always assigned back to main thread context before it is closed. aio_set_fd_handler() already deals with all the necessary synchronization when moving an fd between AioContext-s so no extra code is needed to manage this. Reported-by: Julien Grall <jgrall@amazon.com> Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> Message-Id: <20191216143451.19024-1-pdurrant@amazon.com> Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
843 lines
25 KiB
C
843 lines
25 KiB
C
/*
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* Copyright (c) 2018 Citrix Systems Inc.
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* (c) Gerd Hoffmann <kraxel@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; under version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, see <http://www.gnu.org/licenses/>.
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#include "qemu/osdep.h"
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#include "qemu/error-report.h"
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#include "qemu/main-loop.h"
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#include "qapi/error.h"
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#include "hw/xen/xen_common.h"
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#include "hw/block/xen_blkif.h"
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#include "sysemu/block-backend.h"
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#include "sysemu/iothread.h"
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#include "xen-block.h"
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typedef struct XenBlockRequest {
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blkif_request_t req;
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int16_t status;
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off_t start;
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QEMUIOVector v;
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void *buf;
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size_t size;
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int presync;
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int aio_inflight;
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int aio_errors;
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XenBlockDataPlane *dataplane;
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QLIST_ENTRY(XenBlockRequest) list;
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BlockAcctCookie acct;
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} XenBlockRequest;
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struct XenBlockDataPlane {
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XenDevice *xendev;
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XenEventChannel *event_channel;
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unsigned int *ring_ref;
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unsigned int nr_ring_ref;
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void *sring;
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int protocol;
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blkif_back_rings_t rings;
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int more_work;
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QLIST_HEAD(inflight_head, XenBlockRequest) inflight;
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QLIST_HEAD(freelist_head, XenBlockRequest) freelist;
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int requests_total;
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int requests_inflight;
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unsigned int max_requests;
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BlockBackend *blk;
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unsigned int sector_size;
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QEMUBH *bh;
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IOThread *iothread;
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AioContext *ctx;
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};
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static void reset_request(XenBlockRequest *request)
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{
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memset(&request->req, 0, sizeof(request->req));
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request->status = 0;
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request->start = 0;
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request->size = 0;
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request->presync = 0;
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request->aio_inflight = 0;
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request->aio_errors = 0;
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request->dataplane = NULL;
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memset(&request->list, 0, sizeof(request->list));
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memset(&request->acct, 0, sizeof(request->acct));
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qemu_iovec_reset(&request->v);
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}
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static XenBlockRequest *xen_block_start_request(XenBlockDataPlane *dataplane)
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{
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XenBlockRequest *request = NULL;
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if (QLIST_EMPTY(&dataplane->freelist)) {
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if (dataplane->requests_total >= dataplane->max_requests) {
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goto out;
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}
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/* allocate new struct */
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request = g_malloc0(sizeof(*request));
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request->dataplane = dataplane;
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/*
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* We cannot need more pages per requests than this, and since we
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* re-use requests, allocate the memory once here. It will be freed
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* xen_block_dataplane_destroy() when the request list is freed.
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*/
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request->buf = qemu_memalign(XC_PAGE_SIZE,
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BLKIF_MAX_SEGMENTS_PER_REQUEST *
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XC_PAGE_SIZE);
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dataplane->requests_total++;
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qemu_iovec_init(&request->v, 1);
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} else {
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/* get one from freelist */
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request = QLIST_FIRST(&dataplane->freelist);
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QLIST_REMOVE(request, list);
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}
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QLIST_INSERT_HEAD(&dataplane->inflight, request, list);
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dataplane->requests_inflight++;
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out:
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return request;
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}
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static void xen_block_finish_request(XenBlockRequest *request)
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{
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XenBlockDataPlane *dataplane = request->dataplane;
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QLIST_REMOVE(request, list);
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dataplane->requests_inflight--;
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}
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static void xen_block_release_request(XenBlockRequest *request)
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{
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XenBlockDataPlane *dataplane = request->dataplane;
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QLIST_REMOVE(request, list);
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reset_request(request);
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request->dataplane = dataplane;
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QLIST_INSERT_HEAD(&dataplane->freelist, request, list);
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dataplane->requests_inflight--;
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}
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/*
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* translate request into iovec + start offset
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* do sanity checks along the way
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*/
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static int xen_block_parse_request(XenBlockRequest *request)
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{
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XenBlockDataPlane *dataplane = request->dataplane;
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size_t len;
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int i;
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switch (request->req.operation) {
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case BLKIF_OP_READ:
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break;
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case BLKIF_OP_FLUSH_DISKCACHE:
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request->presync = 1;
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if (!request->req.nr_segments) {
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return 0;
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}
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/* fall through */
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case BLKIF_OP_WRITE:
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break;
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case BLKIF_OP_DISCARD:
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return 0;
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default:
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error_report("error: unknown operation (%d)", request->req.operation);
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goto err;
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};
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if (request->req.operation != BLKIF_OP_READ &&
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blk_is_read_only(dataplane->blk)) {
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error_report("error: write req for ro device");
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goto err;
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}
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request->start = request->req.sector_number * dataplane->sector_size;
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for (i = 0; i < request->req.nr_segments; i++) {
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if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
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error_report("error: nr_segments too big");
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goto err;
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}
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if (request->req.seg[i].first_sect > request->req.seg[i].last_sect) {
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error_report("error: first > last sector");
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goto err;
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}
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if (request->req.seg[i].last_sect * dataplane->sector_size >=
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XC_PAGE_SIZE) {
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error_report("error: page crossing");
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goto err;
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}
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len = (request->req.seg[i].last_sect -
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request->req.seg[i].first_sect + 1) * dataplane->sector_size;
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request->size += len;
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}
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if (request->start + request->size > blk_getlength(dataplane->blk)) {
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error_report("error: access beyond end of file");
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goto err;
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}
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return 0;
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err:
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request->status = BLKIF_RSP_ERROR;
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return -1;
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}
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static int xen_block_copy_request(XenBlockRequest *request)
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{
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XenBlockDataPlane *dataplane = request->dataplane;
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XenDevice *xendev = dataplane->xendev;
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XenDeviceGrantCopySegment segs[BLKIF_MAX_SEGMENTS_PER_REQUEST];
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int i, count;
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bool to_domain = (request->req.operation == BLKIF_OP_READ);
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void *virt = request->buf;
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Error *local_err = NULL;
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if (request->req.nr_segments == 0) {
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return 0;
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}
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count = request->req.nr_segments;
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for (i = 0; i < count; i++) {
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if (to_domain) {
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segs[i].dest.foreign.ref = request->req.seg[i].gref;
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segs[i].dest.foreign.offset = request->req.seg[i].first_sect *
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dataplane->sector_size;
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segs[i].source.virt = virt;
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} else {
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segs[i].source.foreign.ref = request->req.seg[i].gref;
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segs[i].source.foreign.offset = request->req.seg[i].first_sect *
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dataplane->sector_size;
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segs[i].dest.virt = virt;
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}
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segs[i].len = (request->req.seg[i].last_sect -
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request->req.seg[i].first_sect + 1) *
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dataplane->sector_size;
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virt += segs[i].len;
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}
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xen_device_copy_grant_refs(xendev, to_domain, segs, count, &local_err);
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if (local_err) {
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error_reportf_err(local_err, "failed to copy data: ");
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request->aio_errors++;
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return -1;
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}
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return 0;
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}
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static int xen_block_do_aio(XenBlockRequest *request);
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static int xen_block_send_response(XenBlockRequest *request);
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static void xen_block_complete_aio(void *opaque, int ret)
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{
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XenBlockRequest *request = opaque;
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XenBlockDataPlane *dataplane = request->dataplane;
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aio_context_acquire(dataplane->ctx);
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if (ret != 0) {
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error_report("%s I/O error",
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request->req.operation == BLKIF_OP_READ ?
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"read" : "write");
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request->aio_errors++;
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}
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request->aio_inflight--;
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if (request->presync) {
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request->presync = 0;
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xen_block_do_aio(request);
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goto done;
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}
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if (request->aio_inflight > 0) {
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goto done;
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}
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switch (request->req.operation) {
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case BLKIF_OP_READ:
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/* in case of failure request->aio_errors is increased */
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if (ret == 0) {
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xen_block_copy_request(request);
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}
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break;
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case BLKIF_OP_WRITE:
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case BLKIF_OP_FLUSH_DISKCACHE:
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default:
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break;
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}
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request->status = request->aio_errors ? BLKIF_RSP_ERROR : BLKIF_RSP_OKAY;
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xen_block_finish_request(request);
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switch (request->req.operation) {
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case BLKIF_OP_WRITE:
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case BLKIF_OP_FLUSH_DISKCACHE:
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if (!request->req.nr_segments) {
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break;
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}
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/* fall through */
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case BLKIF_OP_READ:
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if (request->status == BLKIF_RSP_OKAY) {
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block_acct_done(blk_get_stats(dataplane->blk), &request->acct);
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} else {
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block_acct_failed(blk_get_stats(dataplane->blk), &request->acct);
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}
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break;
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case BLKIF_OP_DISCARD:
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default:
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break;
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}
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if (xen_block_send_response(request)) {
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Error *local_err = NULL;
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xen_device_notify_event_channel(dataplane->xendev,
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dataplane->event_channel,
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&local_err);
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if (local_err) {
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error_report_err(local_err);
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}
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}
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xen_block_release_request(request);
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if (dataplane->more_work) {
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qemu_bh_schedule(dataplane->bh);
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}
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done:
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aio_context_release(dataplane->ctx);
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}
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static bool xen_block_split_discard(XenBlockRequest *request,
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blkif_sector_t sector_number,
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uint64_t nr_sectors)
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{
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XenBlockDataPlane *dataplane = request->dataplane;
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int64_t byte_offset;
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int byte_chunk;
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uint64_t byte_remaining;
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uint64_t sec_start = sector_number;
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uint64_t sec_count = nr_sectors;
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/* Wrap around, or overflowing byte limit? */
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if (sec_start + sec_count < sec_count ||
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sec_start + sec_count > INT64_MAX / dataplane->sector_size) {
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return false;
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}
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byte_offset = sec_start * dataplane->sector_size;
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byte_remaining = sec_count * dataplane->sector_size;
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do {
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byte_chunk = byte_remaining > BDRV_REQUEST_MAX_BYTES ?
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BDRV_REQUEST_MAX_BYTES : byte_remaining;
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request->aio_inflight++;
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blk_aio_pdiscard(dataplane->blk, byte_offset, byte_chunk,
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xen_block_complete_aio, request);
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byte_remaining -= byte_chunk;
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byte_offset += byte_chunk;
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} while (byte_remaining > 0);
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return true;
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}
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static int xen_block_do_aio(XenBlockRequest *request)
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{
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XenBlockDataPlane *dataplane = request->dataplane;
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if (request->req.nr_segments &&
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(request->req.operation == BLKIF_OP_WRITE ||
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request->req.operation == BLKIF_OP_FLUSH_DISKCACHE) &&
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xen_block_copy_request(request)) {
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goto err;
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}
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request->aio_inflight++;
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if (request->presync) {
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blk_aio_flush(request->dataplane->blk, xen_block_complete_aio,
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request);
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return 0;
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}
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switch (request->req.operation) {
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case BLKIF_OP_READ:
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qemu_iovec_add(&request->v, request->buf, request->size);
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block_acct_start(blk_get_stats(dataplane->blk), &request->acct,
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request->v.size, BLOCK_ACCT_READ);
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request->aio_inflight++;
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blk_aio_preadv(dataplane->blk, request->start, &request->v, 0,
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xen_block_complete_aio, request);
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break;
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case BLKIF_OP_WRITE:
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case BLKIF_OP_FLUSH_DISKCACHE:
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if (!request->req.nr_segments) {
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break;
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}
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qemu_iovec_add(&request->v, request->buf, request->size);
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block_acct_start(blk_get_stats(dataplane->blk), &request->acct,
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request->v.size,
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request->req.operation == BLKIF_OP_WRITE ?
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BLOCK_ACCT_WRITE : BLOCK_ACCT_FLUSH);
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request->aio_inflight++;
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blk_aio_pwritev(dataplane->blk, request->start, &request->v, 0,
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xen_block_complete_aio, request);
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break;
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case BLKIF_OP_DISCARD:
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{
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struct blkif_request_discard *req = (void *)&request->req;
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if (!xen_block_split_discard(request, req->sector_number,
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req->nr_sectors)) {
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goto err;
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}
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break;
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}
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default:
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/* unknown operation (shouldn't happen -- parse catches this) */
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goto err;
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}
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xen_block_complete_aio(request, 0);
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return 0;
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err:
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xen_block_finish_request(request);
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request->status = BLKIF_RSP_ERROR;
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return -1;
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}
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static int xen_block_send_response(XenBlockRequest *request)
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{
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XenBlockDataPlane *dataplane = request->dataplane;
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int send_notify = 0;
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int have_requests = 0;
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blkif_response_t *resp;
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/* Place on the response ring for the relevant domain. */
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switch (dataplane->protocol) {
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case BLKIF_PROTOCOL_NATIVE:
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resp = (blkif_response_t *)RING_GET_RESPONSE(
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&dataplane->rings.native,
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dataplane->rings.native.rsp_prod_pvt);
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break;
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case BLKIF_PROTOCOL_X86_32:
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resp = (blkif_response_t *)RING_GET_RESPONSE(
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&dataplane->rings.x86_32_part,
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dataplane->rings.x86_32_part.rsp_prod_pvt);
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break;
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case BLKIF_PROTOCOL_X86_64:
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resp = (blkif_response_t *)RING_GET_RESPONSE(
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&dataplane->rings.x86_64_part,
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dataplane->rings.x86_64_part.rsp_prod_pvt);
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break;
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default:
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return 0;
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}
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resp->id = request->req.id;
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resp->operation = request->req.operation;
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resp->status = request->status;
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dataplane->rings.common.rsp_prod_pvt++;
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RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&dataplane->rings.common,
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send_notify);
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if (dataplane->rings.common.rsp_prod_pvt ==
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dataplane->rings.common.req_cons) {
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/*
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* Tail check for pending requests. Allows frontend to avoid
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* notifications if requests are already in flight (lower
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* overheads and promotes batching).
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*/
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RING_FINAL_CHECK_FOR_REQUESTS(&dataplane->rings.common,
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have_requests);
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} else if (RING_HAS_UNCONSUMED_REQUESTS(&dataplane->rings.common)) {
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have_requests = 1;
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}
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if (have_requests) {
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dataplane->more_work++;
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}
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return send_notify;
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}
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static int xen_block_get_request(XenBlockDataPlane *dataplane,
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XenBlockRequest *request, RING_IDX rc)
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{
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switch (dataplane->protocol) {
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case BLKIF_PROTOCOL_NATIVE: {
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blkif_request_t *req =
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RING_GET_REQUEST(&dataplane->rings.native, rc);
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memcpy(&request->req, req, sizeof(request->req));
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break;
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}
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case BLKIF_PROTOCOL_X86_32: {
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blkif_x86_32_request_t *req =
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RING_GET_REQUEST(&dataplane->rings.x86_32_part, rc);
|
|
|
|
blkif_get_x86_32_req(&request->req, req);
|
|
break;
|
|
}
|
|
case BLKIF_PROTOCOL_X86_64: {
|
|
blkif_x86_64_request_t *req =
|
|
RING_GET_REQUEST(&dataplane->rings.x86_64_part, rc);
|
|
|
|
blkif_get_x86_64_req(&request->req, req);
|
|
break;
|
|
}
|
|
}
|
|
/* Prevent the compiler from accessing the on-ring fields instead. */
|
|
barrier();
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Threshold of in-flight requests above which we will start using
|
|
* blk_io_plug()/blk_io_unplug() to batch requests.
|
|
*/
|
|
#define IO_PLUG_THRESHOLD 1
|
|
|
|
static bool xen_block_handle_requests(XenBlockDataPlane *dataplane)
|
|
{
|
|
RING_IDX rc, rp;
|
|
XenBlockRequest *request;
|
|
int inflight_atstart = dataplane->requests_inflight;
|
|
int batched = 0;
|
|
bool done_something = false;
|
|
|
|
dataplane->more_work = 0;
|
|
|
|
rc = dataplane->rings.common.req_cons;
|
|
rp = dataplane->rings.common.sring->req_prod;
|
|
xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
|
|
|
|
/*
|
|
* If there was more than IO_PLUG_THRESHOLD requests in flight
|
|
* when we got here, this is an indication that there the bottleneck
|
|
* is below us, so it's worth beginning to batch up I/O requests
|
|
* rather than submitting them immediately. The maximum number
|
|
* of requests we're willing to batch is the number already in
|
|
* flight, so it can grow up to max_requests when the bottleneck
|
|
* is below us.
|
|
*/
|
|
if (inflight_atstart > IO_PLUG_THRESHOLD) {
|
|
blk_io_plug(dataplane->blk);
|
|
}
|
|
while (rc != rp) {
|
|
/* pull request from ring */
|
|
if (RING_REQUEST_CONS_OVERFLOW(&dataplane->rings.common, rc)) {
|
|
break;
|
|
}
|
|
request = xen_block_start_request(dataplane);
|
|
if (request == NULL) {
|
|
dataplane->more_work++;
|
|
break;
|
|
}
|
|
xen_block_get_request(dataplane, request, rc);
|
|
dataplane->rings.common.req_cons = ++rc;
|
|
done_something = true;
|
|
|
|
/* parse them */
|
|
if (xen_block_parse_request(request) != 0) {
|
|
switch (request->req.operation) {
|
|
case BLKIF_OP_READ:
|
|
block_acct_invalid(blk_get_stats(dataplane->blk),
|
|
BLOCK_ACCT_READ);
|
|
break;
|
|
case BLKIF_OP_WRITE:
|
|
block_acct_invalid(blk_get_stats(dataplane->blk),
|
|
BLOCK_ACCT_WRITE);
|
|
break;
|
|
case BLKIF_OP_FLUSH_DISKCACHE:
|
|
block_acct_invalid(blk_get_stats(dataplane->blk),
|
|
BLOCK_ACCT_FLUSH);
|
|
default:
|
|
break;
|
|
};
|
|
|
|
if (xen_block_send_response(request)) {
|
|
Error *local_err = NULL;
|
|
|
|
xen_device_notify_event_channel(dataplane->xendev,
|
|
dataplane->event_channel,
|
|
&local_err);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
}
|
|
}
|
|
xen_block_release_request(request);
|
|
continue;
|
|
}
|
|
|
|
if (inflight_atstart > IO_PLUG_THRESHOLD &&
|
|
batched >= inflight_atstart) {
|
|
blk_io_unplug(dataplane->blk);
|
|
}
|
|
xen_block_do_aio(request);
|
|
if (inflight_atstart > IO_PLUG_THRESHOLD) {
|
|
if (batched >= inflight_atstart) {
|
|
blk_io_plug(dataplane->blk);
|
|
batched = 0;
|
|
} else {
|
|
batched++;
|
|
}
|
|
}
|
|
}
|
|
if (inflight_atstart > IO_PLUG_THRESHOLD) {
|
|
blk_io_unplug(dataplane->blk);
|
|
}
|
|
|
|
return done_something;
|
|
}
|
|
|
|
static void xen_block_dataplane_bh(void *opaque)
|
|
{
|
|
XenBlockDataPlane *dataplane = opaque;
|
|
|
|
aio_context_acquire(dataplane->ctx);
|
|
xen_block_handle_requests(dataplane);
|
|
aio_context_release(dataplane->ctx);
|
|
}
|
|
|
|
static bool xen_block_dataplane_event(void *opaque)
|
|
{
|
|
XenBlockDataPlane *dataplane = opaque;
|
|
|
|
return xen_block_handle_requests(dataplane);
|
|
}
|
|
|
|
XenBlockDataPlane *xen_block_dataplane_create(XenDevice *xendev,
|
|
BlockBackend *blk,
|
|
unsigned int sector_size,
|
|
IOThread *iothread)
|
|
{
|
|
XenBlockDataPlane *dataplane = g_new0(XenBlockDataPlane, 1);
|
|
|
|
dataplane->xendev = xendev;
|
|
dataplane->blk = blk;
|
|
dataplane->sector_size = sector_size;
|
|
|
|
QLIST_INIT(&dataplane->inflight);
|
|
QLIST_INIT(&dataplane->freelist);
|
|
|
|
if (iothread) {
|
|
dataplane->iothread = iothread;
|
|
object_ref(OBJECT(dataplane->iothread));
|
|
dataplane->ctx = iothread_get_aio_context(dataplane->iothread);
|
|
} else {
|
|
dataplane->ctx = qemu_get_aio_context();
|
|
}
|
|
dataplane->bh = aio_bh_new(dataplane->ctx, xen_block_dataplane_bh,
|
|
dataplane);
|
|
|
|
return dataplane;
|
|
}
|
|
|
|
void xen_block_dataplane_destroy(XenBlockDataPlane *dataplane)
|
|
{
|
|
XenBlockRequest *request;
|
|
|
|
if (!dataplane) {
|
|
return;
|
|
}
|
|
|
|
while (!QLIST_EMPTY(&dataplane->freelist)) {
|
|
request = QLIST_FIRST(&dataplane->freelist);
|
|
QLIST_REMOVE(request, list);
|
|
qemu_iovec_destroy(&request->v);
|
|
qemu_vfree(request->buf);
|
|
g_free(request);
|
|
}
|
|
|
|
qemu_bh_delete(dataplane->bh);
|
|
if (dataplane->iothread) {
|
|
object_unref(OBJECT(dataplane->iothread));
|
|
}
|
|
|
|
g_free(dataplane);
|
|
}
|
|
|
|
void xen_block_dataplane_stop(XenBlockDataPlane *dataplane)
|
|
{
|
|
XenDevice *xendev;
|
|
|
|
if (!dataplane) {
|
|
return;
|
|
}
|
|
|
|
xendev = dataplane->xendev;
|
|
|
|
aio_context_acquire(dataplane->ctx);
|
|
if (dataplane->event_channel) {
|
|
/* Only reason for failure is a NULL channel */
|
|
xen_device_set_event_channel_context(xendev, dataplane->event_channel,
|
|
qemu_get_aio_context(),
|
|
&error_abort);
|
|
}
|
|
/* Xen doesn't have multiple users for nodes, so this can't fail */
|
|
blk_set_aio_context(dataplane->blk, qemu_get_aio_context(), &error_abort);
|
|
aio_context_release(dataplane->ctx);
|
|
|
|
/*
|
|
* Now that the context has been moved onto the main thread, cancel
|
|
* further processing.
|
|
*/
|
|
qemu_bh_cancel(dataplane->bh);
|
|
|
|
if (dataplane->event_channel) {
|
|
Error *local_err = NULL;
|
|
|
|
xen_device_unbind_event_channel(xendev, dataplane->event_channel,
|
|
&local_err);
|
|
dataplane->event_channel = NULL;
|
|
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
}
|
|
}
|
|
|
|
if (dataplane->sring) {
|
|
Error *local_err = NULL;
|
|
|
|
xen_device_unmap_grant_refs(xendev, dataplane->sring,
|
|
dataplane->nr_ring_ref, &local_err);
|
|
dataplane->sring = NULL;
|
|
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
}
|
|
}
|
|
|
|
g_free(dataplane->ring_ref);
|
|
dataplane->ring_ref = NULL;
|
|
}
|
|
|
|
void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
|
|
const unsigned int ring_ref[],
|
|
unsigned int nr_ring_ref,
|
|
unsigned int event_channel,
|
|
unsigned int protocol,
|
|
Error **errp)
|
|
{
|
|
XenDevice *xendev = dataplane->xendev;
|
|
Error *local_err = NULL;
|
|
unsigned int ring_size;
|
|
unsigned int i;
|
|
|
|
dataplane->nr_ring_ref = nr_ring_ref;
|
|
dataplane->ring_ref = g_new(unsigned int, nr_ring_ref);
|
|
|
|
for (i = 0; i < nr_ring_ref; i++) {
|
|
dataplane->ring_ref[i] = ring_ref[i];
|
|
}
|
|
|
|
dataplane->protocol = protocol;
|
|
|
|
ring_size = XC_PAGE_SIZE * dataplane->nr_ring_ref;
|
|
switch (dataplane->protocol) {
|
|
case BLKIF_PROTOCOL_NATIVE:
|
|
{
|
|
dataplane->max_requests = __CONST_RING_SIZE(blkif, ring_size);
|
|
break;
|
|
}
|
|
case BLKIF_PROTOCOL_X86_32:
|
|
{
|
|
dataplane->max_requests = __CONST_RING_SIZE(blkif_x86_32, ring_size);
|
|
break;
|
|
}
|
|
case BLKIF_PROTOCOL_X86_64:
|
|
{
|
|
dataplane->max_requests = __CONST_RING_SIZE(blkif_x86_64, ring_size);
|
|
break;
|
|
}
|
|
default:
|
|
error_setg(errp, "unknown protocol %u", dataplane->protocol);
|
|
return;
|
|
}
|
|
|
|
xen_device_set_max_grant_refs(xendev, dataplane->nr_ring_ref,
|
|
&local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto stop;
|
|
}
|
|
|
|
dataplane->sring = xen_device_map_grant_refs(xendev,
|
|
dataplane->ring_ref,
|
|
dataplane->nr_ring_ref,
|
|
PROT_READ | PROT_WRITE,
|
|
&local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto stop;
|
|
}
|
|
|
|
switch (dataplane->protocol) {
|
|
case BLKIF_PROTOCOL_NATIVE:
|
|
{
|
|
blkif_sring_t *sring_native = dataplane->sring;
|
|
|
|
BACK_RING_INIT(&dataplane->rings.native, sring_native, ring_size);
|
|
break;
|
|
}
|
|
case BLKIF_PROTOCOL_X86_32:
|
|
{
|
|
blkif_x86_32_sring_t *sring_x86_32 = dataplane->sring;
|
|
|
|
BACK_RING_INIT(&dataplane->rings.x86_32_part, sring_x86_32,
|
|
ring_size);
|
|
break;
|
|
}
|
|
case BLKIF_PROTOCOL_X86_64:
|
|
{
|
|
blkif_x86_64_sring_t *sring_x86_64 = dataplane->sring;
|
|
|
|
BACK_RING_INIT(&dataplane->rings.x86_64_part, sring_x86_64,
|
|
ring_size);
|
|
break;
|
|
}
|
|
}
|
|
|
|
dataplane->event_channel =
|
|
xen_device_bind_event_channel(xendev, event_channel,
|
|
xen_block_dataplane_event, dataplane,
|
|
&local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto stop;
|
|
}
|
|
|
|
aio_context_acquire(dataplane->ctx);
|
|
/* If other users keep the BlockBackend in the iothread, that's ok */
|
|
blk_set_aio_context(dataplane->blk, dataplane->ctx, NULL);
|
|
/* Only reason for failure is a NULL channel */
|
|
xen_device_set_event_channel_context(xendev, dataplane->event_channel,
|
|
dataplane->ctx, &error_abort);
|
|
aio_context_release(dataplane->ctx);
|
|
|
|
return;
|
|
|
|
stop:
|
|
xen_block_dataplane_stop(dataplane);
|
|
}
|